对溴苯酚合成工艺

Preparation of para-bromophenol by selective bromination of phenol

采用正交试验考察了反应物浓度、反应温度、溴滴加时间对直接溴化制备对溴苯酚产率和苯酚转化率的影响。适宜的工艺条件为 :反应温度 0℃ ,加料时间 90min ,溴与苯酚的摩尔比 1.1,溴与溶剂的质量比为 0 .5 9,苯酚与溶剂的质量比为 1.0 4。在上述条件下 ,苯酚的转化率高达 99.4 % ,对溴苯酚产率为 96 % ,对邻比为 85。反应产物经分离、提纯等工艺 ,产品的纯度达到 98.5 %。

The reaction rule of preparation of para bromophenol by selective bromination of phenol was studied. Based on experiments, suitable technological conditions were obtained. When ethyl acetate was used as solvent, the temperature was 0 ℃,the ratio of Br\-2 and phenol was 1.1(by mol), the reaction last for 90 min, the ratio of Br 2 and solvent was 0.59(by wt),the ratio of phenol and solvent was 1.04(by wt). In these conditions the conversion of phenol could amount to 99.4%, and the yield of para bromophenol reached 96%,the ratio of para bromophenol to meta bromophenol was 85.The purity of para bromophenol could reach to 98.5%.